Depression worsens the readings on a barometer of death risk for heart patients.

That barometer is a test that measures vascular endothelial function. That is, it measures how well one's blood vessels are working.

Heart patients who aren't depressed do better on this test than those who report many depressive symptoms, say Andrew Sherwood, PhD, Alan L. Hinderliter, MD, and colleagues at Duke University and the University of North Carolina. The findings appear in the Aug. 16 issue of the Journal of the American College of Cardiology.

"The findings suggest that [doctors] should evaluate patients with [heart] disease for depressive symptoms -- and give tentative support for referring those patients for therapy," Hinderliter says in a news release.

Read WebMD's "Depression, Heart Failure Closely Linked"

Antidepressants May Help

The researchers looked at 143 patients with heart disease. They had suffered a heart attack, bypass surgery, angioplasty, or a blocked artery. None was physically active. All had suffered an exercise-induced reduction in blood flow to the heart in the last year.

Patients who reported symptoms of depression did significantly worse on a test of blood vessel function. That may explain why depression is a known risk factor for bad outcomes in people with heart disease.

Patients taking antidepressants, however, tended to do well on the blood vessel function test.

The study does not prove that depression causes poor blood vessel function -- or that antidepressants reverse this outcome. Nevertheless, Washington University psychiatry professor Robert Carney, PhD, says the findings have important implications. Carney, who was not connected with the study, reviewed the findings for the American College of Cardiology.

"The study adds another piece to the puzzle of how depression may increase the risk for cardiac events, including death," Carney says in a news release. "The results of this and similar studies suggest that this risk may be reduced if depression is recognized and treated."

Read WebMD's "Many Emotions Can Damage the Heart"

By Daniel J. DeNoon, reviewed by Brunilda Nazario, MD

SOURCES: Sherwood, A. Journal of the American College of Cardiology, Aug. 15, 2005; vol 46: pp 656-659. News release, American College of Cardiology.